Liquid atomising devices

ABSTRACT

A liquid atomising device particularly for a gas turbine engine flame tube comprising a tubular body through which air can flow, an air swirler within the downstream end of the body, a fluid supply passage to a plurality of nozzle holes arranged to inject fuel transversely into the air stream downstream of the swirler, each hole being radially directed and being adjacent the root of a swirler blade, the tubular body extending only over the axial length of the swirler and being surrounded by a further swirler of different air flow characteristic.

United States Patent Gerrard (45] Dec. 23, 1975 LIQUID ATOMISING DEVICES 3.570,:42 3/1971 Leonardi et 60/39.?4 R 3.608.831 9/l97l Accrington 239/406 [75] Inventor gig fi Gerrard Blackburn 3.713.588 1/1973 Sharpe 239/400 [73] Assignee: Lucas Aerospace Limit d, Primary Examiner-John J. Love Birmingham, E gland Attorney, Agent, or Firm-Holman & Stern [22] Filed: Nov. 5, 1973 [57] ABSTRACT [21] PP N04 412,821 A liquid'atomising device particularly for a gas turbine engine flame tube comprising a tubular body through 52 us. Cl 239/400; 239/406; 60139.74 R which air can swirler Within 511 M. 0. B05B 1/34 Stream end of the y. a fluid supply passage to a 581 Field of Search 239/400, 403-406, plurality of nozzle holes arranged to inject fuel trans- 239/425. "3974 R versely into the air stream downstream of the swirler, each hole being radially directed and being adjacent [5 References Cited the root of a swirler blade, the tubular body extending only over the axial length of the swirler and being sur- 1 567 482 i PATENTS 239/404 rounded by a further swirler of different air flow charn ony 3.231054 2/l966 Jackson et al. 60/3934 R acteflsnc. 3.254.846 6/[966 Schreter et al. 239/406 x 3 Claims, 5 Drawing Figures E1! 04 1 n An ilk U.S. Patent Dec. 23, 1975 Sheetlof3 3,927 835 A ///AA////////// \l g w II I,

will! US. Patent Dec. 23, 1975 Sheet 2 of3 3,927,835

US. Patent Dec. 23, 1975 Sheet 3 of3 3,927,835

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LIQUID ATOMISING DEVICES This invention relates to liquid atomising devices particularly liquid fuel sprayers for use in gas turbine engines. In particular it concerns such a device comprising a tubular body through which, in use, air is caused to flow, an air swirler within the downstream end of the body and formed of a plurality of blades, a passage within the body for a liquid, and nozzle means comprising a plurality of holes communicating with the said passage and arranged to inject liquid for atomisation into the air-stream downstream of the said swirler in a direction transverse to the airflow, each said hole being adjacent the root of an associated blade and being directed radially from the axis of the said body, the tubular body extending substantially only over the axial length of the swirler and this being surrounded by a further swirler of different air flow characteristics.

It is the object of this invention to provide a liquid atomising device which allows easy access in certain installations and to allow for limited movement between the components in the event of uneven heating during use, to minimise stressing in said components.

According to the present invention a liquid atomising device of the kind described in which the tubular body extends substantially only over the axial length of the swirler, and this is surrounded by a further swirler of different air flow characteristic.

The invention will now be described by way of example with reference to the accompanying drawings in which:

FIG. 1 is a diagramatic crosssectional view of a flame tube for a gas turbine engine incorporating a sprayer constructed in accordance with the invention.

FIG. 2 is an end elevation view.

FIG. 3 is a diagramatic cross-sectional view similar to FIG. 1, of an alternative construction.

FIG. 4 is an enlarged section view of the swirler assembly in the construction shown in FIG. 3.

FIG. 5 is a cross-sectional view of a ring incorporated in the assembly shown in FIG. 4.

With reference to FIGS. I and 2, there is shown a flame tube of annular form enclosed within an annular air jacket. The air jacket is defined by inner and outer tubular casings l0 and II and the flame tube similarly has inner and outer casings I2 and 13. The flame tube casings 12 and 13 are formed from a plurality of tubular members connected by respective apertured rings 14. The annular rings of the flame tube casings have plunged holes 15. Air flows from the airjacket through the apertured rings 14 into the interior of the flame tube along the inner and outer walls I2 and 13 thereof, for the purpose of cooling the walls. The plunged holes 15 are for entering of combustion and dilution air. The flame tube inner and outer casing I2 and I3 converge at the upstream end and are connected to form an annular nose 16. At the downstream end the casings I2 and I3 converge towards an annular outlet I7.

The inner and outer air jacket casings I0 and II also converge at the upstream end to form an annular inlet I8 and in conventional manner the air jacket casings are provided with means for connection to the engine at their ends respectively.

At equiangularly spaced intervals around the flame tube there are circular openings in the nose 16. In these are secured respective circular ducts I9.

Each of the ducts carries a corrugated spacer strip 20 within which is carried a swirler assembly. The swirler assemblies are carried in respective flare plates 21 secured in the upstream end of the flame tube. The flare plates 21 are generally of segmental configuration and are connected to the flame tube casings I2 and 13 by respective joggled flanges which are drilled to allow access for cooling air. The surfaces of the flare plates surrounding the swirler assembly are moreover apertured to allow access for additional combustion air into the upstream combustion zone of the flame tube.

Supported in the air jacket outer casing 11 is a fuel supply pipe 22 carrying at its end a nozzle 23. The nozzle has a plurality of outlet holes 24 in a nose portion extending just beyond the swirler assembly. These holes are moreover directed radially with respect to the access of the body of the nozzle, these holes being disposed adjacent the roots of associated blades of the inner swirler (to be described). The holes 24 all communicate with a central passage within the nozzle through which the supply of fuel is delivered from the fuel supply pipe 22.

The swirler assembly comprises inner and outer sets of swirler blades 25 and 26. The inner swirler blades are mounted upon an inner ring 27 engaged on the external cylindrical surface of the nozzle 23. The outer edges of the blades of the outer swirler 26 are moreover connected to an outer ring 28 which is welded at one end to the flare plate 21 and its other end is engaged in the corrugated spacer 20.

Connecting the inner and outer swirlers there is a sliding joint which allows some axial movement between the swirlers, and also allows some movement of the inner swirler relatively to the outer swirler in the direction which is radial with respect to the centre of the engine.

This sliding arrangement is accomplished by means of rings 29 and 30 connected to the external edges of the inner swirler blades 25 and to the internal edges of the outer swirler blades 26 respectively. The ring 29 carries a split piston ring 31 in a groove formed between a pair of abutments formed on its outside surface. This piston ring 31 engages on a cylindrical surface of the ring 30. Since the piston ring 31 is larger in diameter than the groove which it occupies in the ring 29 it is possible for some movement of said ring 29 to take place relatively to said piston ring and therefore relatively to the ring 30 surrounding it. Moreover since the piston ring 31 engages on a cylindrical surface of the ring 30 it is possible for relative axial movement between the rings 29 and 30 to take place.

To support the flame tube relatively to the air jacket there are a plurality of support pins 32 extending radially with respect to the centre of te engine. These are disposed at the positions of the swirler assemblies respectively and allow some radial movement of the flame tube relatively to the air jacket casings;

The FIG. 3 construction has inner and outer air jacket casings I0 and II, similar to those shown in FIG. I. These converge at the upstream end to form an annular inlet at 18.

Within these are inner and outer flame tube casings l2 and I3 which converge at the downstream end to form an outlet annulus 17.

At the upstream end the casing 12 and I3 converge to form a narrow annular inlet slot 40 which at equiangularly spaced intervals is interupted by a tubular duct 41. This duct 4] is flared at its downstream end and engages on the outside of a swirler assembly of circular form. Connected to each swirler assembly in similar manner to those of the FIG. I construction are respective flare plates 42 which are connected to the flame tube casing 12 and 13 by respective joggled flanges.

The swirler assembly comprises inner and outer sets of swirler blades 43 and 44. The inner set is carried on a ring 45 which engages a fuel nozzle 46 similar to that shown in the FIG. 1 construction. This nozzle is in this case connected to a supply pipe 47. To support the flame tube relatively to the airjacket there are a plurality of support pins (not shown) extending radially with respect to the centre of the engine in similar manner to FIG. 1.

As shown in FIG. 4, the two sets of swirler blades 43 and 44 are connected by a joint allowing some movement between them in a direction radially of the engine. The outer edges of the blades of the inner swirler are connected to a ring 48 while the inner edges of the blades of the outer swirler are connected to a further ring 49. The ring 48 has a generally flared configuration and on its external surface near its smaller end it has an integral flange 50. A similar flange 51 is provided on the adjacent end of the internal surface of the ring 49. Spaced from the flange 50 of the ring 48 there is attached a separate ring 52 which is also shown in FIG. 5. This ring defines an annular externally presented groove into which the flange S1 of the other ring 49 is located. Since however the flange 51 does not engage to the bottom of said annular groove there is provision for movement of the swirlers relatively to one another radially of the assembly and thus principally radially with respect to the engine centre line.

To locate the swirlers to prevent relative rotation between them the ring 52 has a small extension 53 which engages in a corresponding slot in the flange 51 of the ring 49.

I claim:

1. A liquid atomising device comprising a tubular body through which, in use, air is caused to flow, an air swirler within the downstream end of the body and formed of a plurality of blades, a passage within the body for a liquid and an elongated nozzle having a plurality of holes communicating with the said passage and arranged to inject liquid for atomisation into the airstream downstream of said swirler in a direction transverse to the air flow, each said hole being adjacent to the root of an associated blade of the swirler and being directed radially from the axis of said body, the tubular body extending substantially only over the axial length of the swirler and this being surrounded by a further swirler of different air flow characteristics, means permitting limited movement between the nozzle and the further swirler in a direction transversely with respect to the length of the nozzle and the body being formed by a ring on the outer periphery of the inner swirlcr and a further ring on the inner periphery of the further swirler, these rings being connected.

2. A liquid atomising device comprising a tubular body through which, in use, air is caused to flow, an air swirler within the downstream end of the body and formed of a plurality of blades, a passage within the body for liquid, and an elongated nozzle having a plu rality of holes communicating with the said passage and arranged to inject liquid for atomisation into the airstream downstream of the said swirler in a direction transverse to the airflow, each said hold being adjacent the root of an associated blade of the swirler and being directed radially from the axis of the said body, the tubular body extending substantially only over the axial length of the swirler and this being surrounded by a further swirler of different air flow characteristics, the tubular body being formed by a ring connected to the outer periphery of the inner swirler, said ring being provided with a sliding connection with a ring provided on the inner periphery of the further swirler, said rings being provided with respective elements of a piston ring and groove combination forming a sliding connection there between.

3. A liquid atomising device comprising a tubular body through which, in use, air is caused to flow, an air swirler within the downstream end of the body and formed of a plurality of blades, a passage within the body for a liquid, and an elongated nozzle having a plurality of holes communicating with the said passage and arranged to inject liquid for atomisation into the air-stream downstream of the said swirler in a direction transverse to the airflow, each said hole being adjacent the root of an associated blade of the swirler and being directed radially from the axis of the said body, the tubular body extending substantially only over the axial length of the swirler and this being surrounded by a further swirler of different air flow characteristics, the tubular body being formed by a ring connected to the outer periphery of the inner swirler, said ring being provided with a sliding connection with a ring provided on the inner periphery of the further swirler, said rings being provided with respective interengaging flanges on the ring on the outer periphery of the inner swirler and the ring on the inner periphery of the further swirler. 

1. A liquid atomising device comprising a tubular body through which, in use, air is caused to flow, an air swirler within the downstream end of the body and formed of a plurality of blades, a passage within the body for a liquid and an elongated nozzle having a plurality of holes communicating with the said passage and arranged to inject liquid for atomisation into the airstream downstream of said swirler in a direction transverse to the air flow, each said hole being adjacent to the root of an associated blade of the swirler and being directed radially from the axis of said body, the tubular body extending substantially only over the axial length of the swirler and this being surrounded by a further swirler of different air flow characteristics, means permitting limited movement between the nozzle and the further swirler in a direction transversely with respect to the length of the nozzle and the body being formed by a ring on the outer periphery of the inner swirler and a further ring on the inner periphery of the further swirler, these rings being connected.
 2. A liquid atomising device comprising a tubular body through which, in use, air is caused to flow, an air swirler within the downstream end of the body and formed of a plurality of blades, a passage within the body for liquid, and an elongated nozzle having a plurality of holes communicating with the said passage and arranged to inject liquid for atomisation into the air-stream downstream of the said swirler in a direction transverse to the airflow, each said hold being adjacent the root of an associated blade of the swirler and being directed radially from the axis of the said body, the tubular body extending substantially only over the axial length of the swirler and this being surrounded by a further swirler of different air flow characteristics, the tubular body being formed by a ring connected to the outer periphery of the inner swirler, said ring being provided with a sliding connection with a ring provided on the inner periphery of the further swirler, sAid rings being provided with respective elements of a piston ring and groove combination forming a sliding connection there between.
 3. A liquid atomising device comprising a tubular body through which, in use, air is caused to flow, an air swirler within the downstream end of the body and formed of a plurality of blades, a passage within the body for a liquid, and an elongated nozzle having a plurality of holes communicating with the said passage and arranged to inject liquid for atomisation into the air-stream downstream of the said swirler in a direction transverse to the airflow, each said hole being adjacent the root of an associated blade of the swirler and being directed radially from the axis of the said body, the tubular body extending substantially only over the axial length of the swirler and this being surrounded by a further swirler of different air flow characteristics, the tubular body being formed by a ring connected to the outer periphery of the inner swirler, said ring being provided with a sliding connection with a ring provided on the inner periphery of the further swirler, said rings being provided with respective interengaging flanges on the ring on the outer periphery of the inner swirler and the ring on the inner periphery of the further swirler. 